The present invention is directed to a mount for constraining an aircraft engine casing against vertical and axial displacements. In particular, the present invention is directed to a single, integrated aircraft engine mount assembly designed to constrain an engine casing supported beneath a wing-pylon by utilizing two forward horizontally opposed trunnions mounted on the centerline of the engine casing along with a pair of aft positioned engine mounts.
Typically, a separate thrust link system is employed to restrain an aircraft engine from movement due to axial thrust forces. Such a constraint system is employed on the Concorde, see FIG. 1, which shows an aft thrust link assembly with a common link between the two aft mounts. Details of the hardware employed on the Concorde mount are shown in FIG. 2. While many engine mount systems are statically determinate, the Concorde system is not. Rather than employing connecting linkages to accommodate various movements as required by the Concorde, the present invention employs a simplified design for maintaining contact between the engine casing and the pair of oppositely disposed mounts without the need for any connecting links.
Many known engine mount systems tend to create a "backbone bending" moment that is eliminated by the present invention. Typical is the type of structure taught in U.S. Pat. Nos. 4,079,981; 5,474,258 and 4,725,019. In each of these assemblies the forward engine mounts are located above the engine centerline. This arrangement can introduce a "backbone bending" moment which would damage the engine and its support equipment unless the stiffness of the assembly is increased by employing additional support structure as typically occurs.
A further approach is shown in U.S. Pat. Nos. 5,238,206 and 4,603,822. In each of these assemblies the aft engine mounts do not take engine thrust loads. In comparison, the present invention functions as a forward engine mount capable of taking engine thrust loads without additional support structure.
While the ability to take engine thrust loads is present in U.S. Pat. No. 4,742,975, this conventional assembly requires the use of two additional mount struts. The present invention eliminates the need for such struts through the unique structure to be explained.
As can be readily seen, existing assemblies usually employ some type of thrust link to prevent axial movement of the engine casing or require additional strut mounts that can be costly and, more importantly, add weight to the aircraft. When the engine mounts are located above the engine centerline, the backbone bending which inherently occurs can significantly reduce the life cycle of the engine and even result in structural failure with catastrophic results. As will become clear, the present invention provides a unique mount assembly which eliminates the problems associated with conventional structures by providing an integrated assembly that can be constructed at a reduced cost as compared to conventional engine mount assemblies.